Method _dataCheck

src/core/core.datasetController.js:365–392

* @private

()

	 * @private
	 */
  _dataCheck() {
    const dataset = this.getDataset();
    const data = dataset.data || (dataset.data = []);
    const _data = this._data;

    // In order to correctly handle data addition/deletion animation (and thus simulate
    // real-time charts), we need to monitor these data modifications and synchronize
    // the internal metadata accordingly.

    if (isObject(data)) {
      const meta = this._cachedMeta;
      this._data = convertObjectDataToArray(data, meta);
    } else if (_data !== data) {
      if (_data) {
        // This case happens when the user replaced the data array instance.
        unlistenArrayEvents(_data, this);
        // Discard old parsed data and stacks
        const meta = this._cachedMeta;
        clearStacks(meta);
        meta._parsed = [];
      }
      if (data && Object.isExtensible(data)) {
        listenArrayEvents(data, this);
      }
      this._syncList = [];
      this._data = data;
    }
  }

  addElements() {
    const meta = this._cachedMeta;